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IMPROVEMENT IN ALLOYS FOR DENTISTS USE.

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TO ALL WHOM IT MAY CONCERN:

Be it known that I M. M. JOHNSTON, of the city of New York, inthe county of New York, and State of New York, have invented an Improvement in Alloys for Dentists Use, forming an alloy never before used for this purpose; and I do hereby declare that the following is a full and exact description thereof.

My invention consists in the addition of either metallic sodium or potassium, or an amalgam of either, to i mercury, for the purpose of facilitating and causing the union of the mercurynwith the various metals, which,- in combination, form amalgam or cement-filling used in-dentistry for preserving teeth, such as silver, tin, cadmium, platina, &c. a 1 To enable others skilled in the arts to make and use my invention, I will proceed to describe itmore particularly.

I take ten pennyweights of pure mercury and add to this, say, one-quarterpennyweight of sodium or potassium, or an equal amount of amalgam of either. This compound or auialgam is now to be added to any alloy of silver, tin, cadmium, platina, &c., such as are commonly used for amalgam or cement-fillings,in the r i same manner as pure mercury would be used, and it will be readily seen that a. union of the alloy and mercury will be much more readily and perfectly eflected than by the use of mercury without the addition of sodium or potassium, or a compound of either. a

I do not confine myself to the proportions of sodium or potassium and mercury above mentioned, but also claim the use of the same in any proportions which will accomplish the desired efl'ect.

What I claim as my invention, and desire to secure by Letters Patent, is-

The use of sodium or potassium, or an alloy of either or both, for the purposes above mcntioned,,iu the preparation of amalgam or cement for filling teeth.

M. JOHNSTON.

Witnesses EDWARD TIMPsoN, THos. VEITOH. 

